When you encounter a roundabout on a road, the best advice is the British adage to “keep calm and carry on."
The new versions of these circular intersections first emerged in 1966 in the United Kingdom, when English engineer Frank Blackmore, then age 50, had the idea to require vehicles entering the circle to yield to oncoming traffic. He further redesigned modern roundabouts to be much smaller than older traffic circles, such as the Arc de Triomphe in Paris, where a dozen streets intersect, or Columbus Circle, at the southwest corner of Central Park in New York City.
The newer roundabouts require vehicles to negotiate sharper curves to enter and travel around them, according to the Insurance Institute for Highway Safety (IIHS), based in Arlington, Virginia. You will find lower speed limits in modern roundabouts than in the bigger traffic circles, also known as rotaries, and the driving rules are different.
"Most are designed well,” says Kevin Rider, a nationally known expert witness and founder of Forensic Human Factors in Columbus, Ohio. “They are traffic-calming devices and highly efficient at lessening the number of conflict points."
Drivers tend to lower their speed in roundabouts because of the sharper curves, which lessens the number of crashes by a third to a half and their severity by as much as 80 percent. Right-angle, left-turn and head-on collisions are eliminated — unlike intersections with traffic lights — according to the IIHS.
Anxious about roundabouts?
If you dread encountering roundabouts, you're not alone. Drivers 50 and older are especially wary of this new generation of circular intersections, in part because they were introduced in the United States several years after most older drivers earned their licenses.
The first modern roundabout in the U.S. was built in 1990 in Las Vegas. Since then, almost 7,500 similar intersections nationwide have been built because they are safer, according to civil engineering firm Kittelson & Associates, in Portland, Oregon. One of the firm's principal engineers, Lee Rodegerdts, has been keeping a database on roundabouts since 1997, in part based on aerial photos.
Even with older drivers’ lack of familiarity, such traffic calming designs benefit the oldest drivers, the IIHS says. From 2014 to 2018, government data shows that more than half of drivers 75 and older involved in fatal crashes had multiple-vehicle wrecks at intersections.
Often the problem is a failure to yield the right of way. Because all traffic flows counterclockwise through a roundabout in the U.S. and more slowly than at a traditional intersection, any collision is more likely to be minor.
The secret to seamless navigation through a roundabout is to remain focused — and yield to traffic already in the circle — experts say. Treat a roundabout like a right turn on red.
"It's very, very easy,” says Jose Hernandez, a veteran driving instructor with Dexterity Driving School in Washington, D.C., who has been teaching there for five years. “You follow the lights. You follow the signs. Follow the arrows on the ground."
Even though his advice sounds easy, roundabouts confuse drivers for many reasons, which may prompt them to make risky maneuvers. Hands-free calling, in-car infotainment systems and dashboard touch-screen technology are among the distractions that cause disorientation, Rider says. Focus is key.
That focus needs to start when a driver approaches the intersection. Many have signs and street markings that indicate the traffic pattern ahead, Hernandez says.
"Look at the picture and memorize it before you enter,” he says. “It's usually visible from far away. It usually has a circle with all of the exits [named]. Then you know what exit you need."
Of course, some drivers are caught unawares. Rider recalled one case of a motorcyclist on an unfamiliar suburban street in South Carolina. The biker crashed over the roundabout's unlit center island and into a fountain. He was critically injured.
Yet even those who anticipate roundabouts should take extra care.
"Most drivers know what the rules are, and we expect everyone else to follow them,” Rider says. “When other drivers fail to follow the rules, we're put in the position of evaluating what's happening, what might happen, and what we need to do to prevent something from happening. When there isn't enough time for a driver to make the best decision, unfortunate and sometimes tragic incidents occur. Safety in roundabouts comes through preparation, patience and progressing through. Don't stop unless you have to."
Learn the roundabout rules
When you approach a roundabout, pay special attention to signs and pavement markings. Then slow down so that you can merge safely into traffic.
"The biggest mistake is the failure to yield properly,” says Kurt Gray, the Bowie, Maryland-based director of driver education at AAA Club Alliance, which covers the District of Columbia and parts of 13 states. “You always have to yield to pedestrians at crosswalks and traffic that's already in the circle. They have the right of way. I think that can be confusing to some drivers."
Other common mistakes:
• Following another car too closely
• Making sudden, last-second moves from one lane to the next
• Driving beside another vehicle in a two-lane roundabout
This last one is “very dangerous because drivers’ mirrors aren't always properly aligned, and another vehicle could be in your blind spot,” Gray says. “Give yourself space so that you have adequate spacing and a margin of error.
"We know that more than 90 percent of crashes are due to driver error,” he says. “All drivers make mistakes. And you have to anticipate that other drivers will make mistakes."
If you miss your exit, don't try to change lanes quickly. Instead, go around the circle again, merge into the correct lane and then exit. No one is counting the number of times that you go around.
"It takes just [a little while] to get back where you started [in the circle],” Gray says. “Don't feel bad about having to go around again."
How do pedestrians and bicyclists cross a roundabout?
No vehicles or pedestrians are allowed to cut across the lanes of a roundabout and to travel straight.
If a bicyclist wants to ride through a roundabout, the rider should stay in the center of the lane, be treated like a car and be able to pedal through. But a bicyclist also can dismount and act like a pedestrian, walking the bike through crosswalks at the entrances and exits for each street, according to the Federal Highway Administration.
Pedestrians who want to go straight will end up taking a longer, half-circle walk just outside the perimeter of the roundabout. Drivers about to enter a roundabout, and soon after leaving it, must yield when cyclists walking their bikes and pedestrians are in the crosswalks.
But people on foot also should be vigilant. Flustered drivers might forget to yield the right of way even though it's the law.